3) The expression is $\"\"$ \ \

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$\"\"$

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$\"\"$

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$\"\"$ ---------------(1) \ \

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$\"\"$

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$\"\"$ ----------------(2) \ \

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Multiply equation (1)*1 and equation (2) * 2

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$\"\"$

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$\"\"$

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$\"\"$

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y value substitute equation (1) \ \

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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